JP3503384B2 - Earth shape measurement device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention actually measures the shape of the surface of the earth or moon or planets, which is approximated to a spheroid, and digitizes it as a coordinate position on a single coordinate system. The present invention relates to an earth shape measuring device that quantifies shapes such as major axis, minor axis and degree of flatness of planets, distance between continents and undulations of the earth's surface, positions of buildings and roads, etc., and generates topographic information of the entire surface. .

[0002]

2. Description of the Related Art FIG. 15 is a diagram for explaining a conventional earth shape measuring method. In the figure, 12 is the earth, 13 is a spheroid, 45a is a point A1 near the first north pole, and 45b is a second point. Points A2 and 46a near the North Pole of B are points B1 near the first equator, points B2 and 46b near the second equator are points B2 and 47a are the first points.
The distance L1, 47b between the two points is the distance L2, 48a between the second two points, and the angle θ between the first earth center and the two points is θ.
Reference numerals 1 and 48b are angles θ2 formed between the second earth center and two points, L1 is a distance between A1 and A2, L2 is a distance between B1 and B2, θ1 is an angle between the earth center and A1 and A2, and θ2 Is the angle between the center of the earth and B1 and B2. In the early earth shape measurement, the earth 12 was regarded as the same as the spheroid 13, and the earth shape was measured by measuring the length of the meridian from the equator to the North Pole, for example, at every latitude. Since the latitude is the angle formed by the vertical line and the equatorial plane at that point, it can be seen that if L1 is smaller than L2 when θ1 = θ2 in the figure, the radius of curvature is smaller near the equator. To find the latitude of a point on the surface of the earth, measure the angle between the zenith and the equator at that point. Since it is difficult to measure the direction of the equator, the angle between the star and the zenith, that is, the zenith distance, is measured when a star with a known declination passes through the meridian. To know the longitude, use the fact that the Earth 12 rotates.
First, a point with zero longitude is set, the time when a star passes the meridian at that point is measured, and then the longitude is obtained from the difference between the two by knowing the time when the same star passes the meridian at the measurement point. Actually, the earth 12 has a shape in which large and small undulations of the surface are added on the spheroid 13,
When creating a topographic map in each country, the dimensional value of the spheroid 13 is assumed, and it is referred to as a reference ellipsoid, which is the basis of the earth shape.

FIG. 16 is a diagram showing a satellite triangulation device which is one of conventional earth shape measuring devices.
2 is the earth, 34 is a geodetic satellite, 35a is the first reference point, 3
5b is a second reference point, 36 is a camera, and 37 is a measurement point.

Next, the principle will be described with reference to FIG. FIG. 17 is a principle diagram of satellite triangulation, in which 12 is the earth, 34 is a geodetic satellite, 38 is the orbit of the geodetic satellite,
39 is a straight line with a known distance, 40 is a straight line with an unknown distance, 4
1 is the position s1 of the geodetic satellite at time t1, 42 is the position s2 of the geodetic satellite at time t2, 35a is the first reference point A, 35b is the second reference point B, and 37 is the measurement point X. Since the geodetic satellite 34 reflects sunlight even though it is dark, the geodetic satellite 34 can be captured by a camera. A timing device (not shown) can determine the RA and declination of the geodetic satellite 34 at the observation time by comparing with the position of the background star. When determining the position of the measuring point X37 from two points whose position coordinates are known, that is, the first reference point A35a and the second reference point B35b, in the figure, the geodetic satellite 34
At the position of S1, the directions of AS1, BS1, and XS1 are determined by simultaneously observing at the first reference point A35a, the second reference point B35b, and the measurement point X37. Since the length of AB is known, the triangle ABS1 is determined. Next, when the geodetic satellite 34 simultaneously observes again at the position S2, the position of the measuring point X37 is geometrically determined as the intersection of XS1 and XS2, and therefore the position coordinate of the measuring point X37 is known. By repeating this principle, the relative shape of each part of the surface of the earth is measured to measure the shape of the earth.

FIG. 18 is a view showing an aerial triangulation device which is one of other conventional earth shape measuring devices. In the figure, 43 is an aircraft, 36 is a camera, 31 is an anti-aircraft sign, 44
Is the field of view of the camera, and 12 is the earth. In the figure, an aerial photograph of the surface of the earth is taken by the camera 36 mounted on the aircraft 43, and the altitude is calculated by stereoscopically viewing an overlapping portion of a plurality of aerial photographs of the same area taken from different positions. Since only the relative height difference within the field of view of the photograph is known in the elevation calculation, the field of view 4 of the camera for installing the aerial photograph by installing the anti-aircraft sign 31 whose position coordinate is known on the ground in advance.
This anti-aircraft sign 31 is photographed in 4 and used as a reference for altitude calculation.

FIG. 19 is a diagram showing one of other conventional earth shape measuring devices. In the figure, 6 is an observation satellite, 9 is an altimeter, and 12 is the earth. In the figure, the altimeter 9 mounted on the observation satellite 6 measures the distance between the ground and the observation satellite 6. As the altimeter 9, there is known a laser radar that emits a laser beam toward the ground and measures the time until the reflected wave is received. Since the orbit of the observation satellite 6 can be analytically grasped, the position and altitude of the earth surface can be measured.

[0007]

[Problems to be Solved by the Invention] Quantitative understanding of the earth's surface shape, such as a flat elliptical shape transformed into a pear shape, is an important theme that helps clarify many phenomena in geophysics, and geodesy. In the same way, it was a problem to measure the surface shape of the earth in a single coordinate system. On the other hand, in the conventional earth shape measuring device, when measuring with a measuring machine on the ground, the position of the point where the measuring machine is installed can be measured with high accuracy, but other places cannot be measured, The undulations of the earth's surface could not be quantified as three-dimensional information. Further, as the number of measurement points increases, the required number of facilities and equipment increases, so there is a problem that enormous cost and labor are required to acquire data on the entire surface of the earth. In addition, it was difficult to acquire the amount of data covering the earth's surface because it was difficult to secure the location of the measuring equipment. In addition, there is a problem that there are some areas that cannot be measured because measurement equipment cannot be installed in polar areas and undeveloped areas.

Further, conventional triangulation, which measures the position of another point as a distance reference between two known points on the ground, cannot measure a long distance enough to sandwich the ocean, so that the distance between two continents is different. There was a problem that the distance between two points between the continent and the island country could not be measured, and the relative position between the continent and the island country could not be determined.

Further, in the measuring method based on the vertical direction,
There was a problem that the vertical direction itself had anisotropy depending on the location due to the bias of gravity caused by the presence of deposits, etc., so it could not be a stable reference.

Further, when performing aerial triangulation from an observation satellite or an aircraft, the absolute angle of the line-of-sight direction of the image pickup device cannot be measured, and the angle change can be measured, but the angle in the reference coordinate system cannot be determined. There was a problem that surveying was not possible.

Further, in the means for analyzing the elevation by stereoscopic vision utilizing the parallax of the image data taken from different positions such as aerial triangulation, only the relative elevation difference within one screen is calculated. There is a problem that the absolute coordinates cannot be known unless there is an anti-aircraft sign whose position and altitude are known on the screen.

Further, in the case of altimeter measurement, if the irradiation beam is wide, the average altitude of the ground surface can be measured, but high-resolution measurement corresponding to small undulations cannot be performed. Since the orbit interval for acquiring data of the entire surface is too narrow, it is difficult to realize a satellite that flies in a proper orbit, and it is difficult to cover the entire surface of the earth within the life span of the satellite. There was a problem that surface observation could not be carried out.

Further, when the longitude is measured with the earth rotation as a reference for determining the time, there is a problem that the absolute time accuracy becomes insufficient due to the fluctuation of the rotation speed due to the movement of the earth rotation axis.
In addition, since the satellite flies at a speed of several kilometers per second, if the time accuracy is poor, the position accuracy cannot be increased.

Further, a plurality of ellipsoids formalizing the ellipsoidal shape of the earth have been proposed. Since the ellipsoids adopted in each country are different and there is a difference of 1 km in the major radius, relative positioning of maps is performed. However, there was a problem that the standard for aligning in a single coordinate system could not be obtained even if it was wanted.

Further, it is difficult to realize data acquisition over the entire surface of the earth because it requires a huge amount of time and labor, and since there is no device for storing the data in a state that can be compared with the past data, the data is acquired multiple times. However, there was a problem that it was difficult to perform statistical processing and to grasp the global aging phenomenon. Also, when data is updated with the progress of measurement technology, enormous amount of data needs to be reacquired each time, and there is a difficulty in feasibility.

Further, in the case of measurement from an aircraft or satellite,
There is a problem that there is no means for performing a correction process later because no related information remains even if there is sway or attitude change of an aircraft or satellite. Especially when an image is acquired using a line sensor, the position and attitude information of the satellite is not known at all imaging timings, so if the attitude of the satellite fluctuates during imaging, the geometric distortion of the image cannot be corrected and the error factor cannot be resolved. There was a problem of becoming.

The equator from the tropics to the subtropics and the polar regions near the North Pole and the South Pole are important regions for grasping the shape of the earth. Conventionally, an optical sensor is used in a device for stereoscopically viewing satellite image data. Therefore, there was a problem that it was not possible to obtain practical data in regions covered by clouds or from high latitude where there is little sunlight reflection to the polar regions.

In addition, there is a problem in that it is impossible to obtain altitude data of the ocean or desert area where it is difficult to find a characteristic point in stereoscopic viewing.

Further, in calculating the absolute value of the altitude by the parallax of the image data, the influence of the shaking of the mounted satellite or aircraft, the position measurement error, and the angle error of the line-of-sight direction is large, and the error of the calculation result is too large for practical use. There was a problem that I could not stand.

Therefore, there is a demand for an earth shape measuring device capable of quantifying the earth shape as three-dimensional information over the entire surface of the earth on a single coordinate system and effectively collecting, maintaining, and managing enormous measurement data. It was

The present invention has been made to solve the above problems, and an earth shape measuring apparatus capable of quantifying the entire earth surface as three-dimensional information by utilizing earth surface image data viewed from space. I will provide a.

Further, there is provided an earth shape measuring apparatus capable of generating a topographic map in which each country's map is aligned with accuracy of about several tens of meters on a single coordinate system.

Further, there is provided an earth shape measuring device capable of measuring the absolute angle of the line of sight of the observation satellite and the image pickup device with respect to the reference coordinate system and capable of measuring the absolute value of the earth shape.

Further, even if there is no equipment on the ground, it is possible to measure only the image data seen from space, so that it is possible to measure data in all areas where human activity does not reach.

Further, by constructing a set of equipment, no other ground equipment is required, and most of the processing can be automated, so that an earth shape measuring apparatus capable of processing enormous data is provided.

Further, there is provided an earth shape measuring device capable of measuring earth surface position coordinates by a single coordinate system operating a navigation satellite.

Further, since the time is managed by using the atomic clocks having high frequency stability and mutually adjusted, the earth shape measuring device capable of measuring with a common time reference regardless of time and place is provided.

Further, since the altitude is analyzed only by using the geometrical features, the earth shape measuring apparatus which is not affected by the local gravity deviation is provided.

Further, since the ground surface is measured by the principle of triangulation from two points whose position coordinates are known, an earth shape measuring apparatus capable of measuring the absolute coordinates of the ground surface is provided.

Further, by storing the image data, the imaged position, and the information on the angle in a database, the data obtained by different imagers can be processed by the earth shape analyzer, so that it becomes possible to use a plurality of satellites and an enormous amount of the entire earth. Provide an earth shape measuring device capable of acquiring various observation data.

Further, by improving the measurement accuracy of time, position and angle, and providing a means for calibrating the values, an earth shape measuring device having sufficiently high accuracy on a global scale is provided.

Further, since the time history of the image pickup timing is attached to the image data and the satellite position and the line-of-sight direction information at the image pickup time can be verified, the earth shape measuring apparatus capable of correcting the attitude variation is provided.

Since a synthetic aperture radar using microwaves can acquire an image of a region covered by clouds and not exposed to sunlight, topographical data in the vicinity of the equator or in the polar regions, which is characteristic of the elliptical shape of the earth. To provide an earth shape measuring device capable of effectively acquiring the.

Further, by recording the measurement data of the altimeter, which measures the time until the reflected wave of the emitted laser arrives to measure the distance, in a database, it is possible to cover a wide area such as the sea or the desert without a feature and in a flat area. Since the shape can be observed and the average elevation over a wide area can be grasped even in the land area, an earth shape measuring device effective for grasping the rough shape of the earth is provided.

[0035]

According to a first aspect of the present invention, there is provided an earth shape measuring apparatus which is an observation satellite equipped with an image pickup device for pointing the surface of the earth, a clock, a signal processing circuit, an antenna, a navigation satellite signal receiver, image data and time. It is composed of a database for recording information and earth shape data, and a navigation satellite.

Further, an image pickup device is mounted on the observation satellite, and a set of images at the same place on the earth acquired by a plurality of observation satellites whose angles formed by the line-of-sight direction and the vertical direction of the image pickup device are different from each other are aligned to match the satellite position. The position and elevation of the earth's surface are analyzed by using the coordinates, the line-of-sight direction, and the parallax.

Further, it is equipped with three or more antennas for receiving the signals of the navigation satellites and a navigation satellite signal receiver, and the position coordinates on the coordinate system adopted by the navigation satellites are clearly measured, and three or more antennas are provided. The line-of-sight direction of the image pickup device is converted as angle data from the position coordinates.

Further, a clock having a high time stability is used to manage the time between the navigation satellite and the observation satellite, and the image data, the satellite position data, and the line-of-sight angle data are managed together.

Further, the earth shape measuring apparatus according to the second aspect of the present invention is an earth-oriented imaging device, a clock, a signal processing circuit, an antenna, an observation satellite equipped with a navigation satellite signal receiver, image data and time information, and the earth. Similar to the first embodiment, it is configured by a database that records shape data and a navigation satellite, and the line-of-sight direction of the imaging device is converted as angle data from the position coordinates of three or more antennas set on the observation satellite. However, as the above-mentioned image pickup device, a plurality of image pickup devices whose angles formed by the line-of-sight direction and the vertical direction are different from each other are provided, and a set of images at the same place on the earth acquired by the different image pickup devices are aligned, and the satellite position is adjusted. The position and elevation of the earth's surface are analyzed by using the coordinates, the line-of-sight direction, and the parallax.

The earth shape measuring apparatus according to the third aspect of the present invention is an earth orienting imaging device, a clock, a signal processing circuit, an antenna, an observation satellite equipped with a navigation satellite signal receiver, image data and time information, and the earth. Similar to the first embodiment, it is configured by a database that records shape data and a navigation satellite, and the line-of-sight direction of the imaging device is converted as angle data from the position coordinates of three or more antennas set on the observation satellite. However, equipped with a line-of-sight direction changing device of the imaging device,
A set of images at the same place on the earth acquired at positions where the angles formed by the line-of-sight direction and the vertical direction are different from each other are matched, and the altitude of the earth's surface is analyzed using satellite position coordinates, line-of-sight direction, and parallax. is there.

The earth shape measuring apparatus according to the fourth aspect of the present invention is an earth orienting imaging device, a clock, a signal processing circuit, an antenna, an observation satellite equipped with a navigation satellite signal receiver, image data and time information, and the earth. Similar to the first embodiment, it is configured by a database that records shape data and a navigation satellite, and the line-of-sight direction of the imaging device is converted as angle data from the position coordinates of three or more antennas set on the observation satellite. However, it is equipped with an attitude changer that changes the attitude of the observation satellite, and the set of images at the same place on the earth acquired in different attitudes that form the line-of-sight direction and the vertical direction This is to analyze the altitude of the earth's surface by utilizing the gaze direction and parallax.

Further, the earth shape measuring apparatus according to the fifth invention uses an imaging radar as an image pickup device.

The earth shape measuring apparatus according to the sixth aspect of the invention comprises an altimeter.

In the earth shape measuring apparatus according to the seventh aspect of the present invention, the signal processing section adds all the image pickup timing times to the image data, transmits the image data to the ground, and records it in the database together with the image data.

The earth shape measuring apparatus according to the eighth aspect of the invention has an anti-aircraft sign whose position coordinates have been measured in advance by a navigation satellite on the surface of the earth and records the position coordinates in the earth shape database.

Further, in the earth shape measuring apparatus according to the ninth aspect of the invention, the observation satellite is equipped with a computer, and the line-of-sight direction of the image pickup device is converted as angle data from the position coordinates of the three antennas in orbit.

[0047]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1. 1 is a block diagram showing a first embodiment of the present invention. In FIG. 1, reference numeral 1a denotes a first surface oriented to the surface of the earth.
Image pickup device 1b, a second image pickup device 2b whose angle formed by the line-of-sight direction and the vertical direction of the image pickup device is different from that of the first image pickup device 1a, 2a is a first clock, 2b is the first clock 2b, and time. The combined second clock, 3 is a navigation satellite signal receiver, 4a is a first antenna for receiving navigation satellite signals, 4b is a second antenna, 4c is a third antenna, 4d is a fourth antenna,
4e is a fifth antenna, 4f is a sixth antenna, 5 is a signal processing circuit, 6a is a first observation satellite flying in an orbit capable of imaging the surface of the earth by the first imager 1a, and 6b is the above-mentioned first satellite. A second observation satellite that flies in an orbit capable of capturing an image of the surface of the earth with the image pickup device 1b of FIG. 2, 7 is a database that records earth surface position coordinate data, image data, and position data and angle data of the observation satellite together with time information. Is a ground station, 11 is a navigation satellite, and 12 is the earth.
Is equipped with a first imaging device 1a, a first clock 2a, a navigation satellite signal receiver 3, a first antenna 4a, a second antenna 4b, a third antenna 4c and a signal processing circuit 5, and a second
The observation satellite 6b is a second image pickup device 1b, a second clock 2b,
The navigation satellite signal receiver 3, the fifth antenna 4d, the sixth antenna 4e, the seventh antenna 4f, and the signal processing circuit 5 are mounted.

In the figure, in the first observation satellite 6a, the first image pickup device 1a picks up an image of the surface of the earth 12 according to the image pickup timing signal generated by the first clock 2a, and the image data is processed by a signal processing circuit. Send to 5. Further, the first clock 2a uses the signal processing circuit 5 to obtain the time information when the imaging timing signal is generated.
Send to. On the other hand, the navigation satellite signal receiver 3 is the first clock 2
The first antenna 4 according to the timing signal generated by a
a, the second antenna 4b, and the third antenna 4c respectively receive the position information of the satellite at that time from the navigation satellite 11 and transmit it to the signal processing circuit 5. The signal processing circuit 5 adds incidental information such as identification information to the received time information, image data, and position data, processes it into a format that can be transmitted to the ground, and transmits it to the ground station 10 via a transmitter (not shown). To do. It goes without saying that the data can also be transmitted via a data relay satellite (not shown). There are two timing signals generated by the first clock 2a, that is, the image pickup timing and the position information acquisition timing, but they do not need to be synchronized with each other as long as the mutual time is accurately recorded, and the respective time information is obtained. Are recorded together with the corresponding image data or position data in the signal processing circuit 5. The image capturing timing is set in the first timepiece 2a based on the timing of starting image acquisition and the interval at which image capturing is repeated. Further, the position information acquisition timing is set in the first timepiece 2a at a frequency sufficient to satisfy the position accuracy required when analyzing the earth surface position coordinates.

Similarly in the second observation satellite 6b, the time information of the second clock 2b, the image data of the second image pickup device 1b, the position data and the incidental information are transmitted to the ground. Next, the ground station 10 receives the information transmitted by the receiver (not shown) and records it in the database. The database 7 records and manages image data, position data, angle data and incidental information. At this time, the angle data is calculated by obtaining the normal direction vector of the plane where the three points are present based on the position coordinates of the three points where the three antennas mounted on the observation satellite 6 are present. Further, a set of image data at the same place on the earth is extracted from the image data obtained by the first image pickup device 1a and the image data obtained by the second image pickup device 1b, and the set of image data is obtained by the earth shape analyzer. Align the corresponding locations in the area and align them, analyze the altitude of the earth's surface using satellite position coordinates, line-of-sight direction and parallax, and digitize the results as the earth surface position coordinates, and attach the identification information etc. After adding the information, record it in the database.

Next, the principle will be described with reference to FIG.
FIG. 2 is a schematic diagram of the shape of the earth and the satellite orbit in the first embodiment of the present invention. In the figure, 6a is a first observation satellite, 6b is a second observation satellite, 11 is a navigation satellite, 12 is the earth, 13 is a spheroid, 14a is the line of sight of the first imaging device,
14b is the line of sight of the second imaging device, 15a is the orbit of the first observation satellite, 15b is the orbit of the second observation satellite, and 16 is the orbit of the navigation satellite. In the present invention, in order to measure the shape of the earth 12 without using the spheroid 13 as a reference for measuring the shape of the earth, and without using the gravity of the earth as a reference for measuring the shape of the earth, the shape of the earth is measured by triangulation from space, which is a position outside the earth. Take measurements. The orbits of observation satellites and navigation satellites themselves are determined by the influence of the earth's gravity. However, since navigation satellites fly at altitudes as high as 2000 km orbit, the influence of gravity bias is small, and, for example, global positioning in the United States. In a device such as the device that has been subjected to sufficient influence correction processing, the position coordinates can be determined without being affected by the changes in the earth's gravity. Therefore, for example, the World Geodetic System used in the global positioning device
Using the geodetic coordinate system called m84, it becomes possible to measure the earth shape on a single coordinate system and determine the position coordinates. The position coordinates of the first observation satellite 6a and the second observation satellite 6b are based on the signals of a plurality of navigation satellites 11
The position coordinates on the coordinate system to be adopted in are determined. A specific example of improving the position accuracy will be described later. Since the position coordinates of satellites change every moment along the orbital direction, it is essential to manage the time using a highly accurate clock that adjusts the time. Therefore, as a clock, an atomic clock such as a quartz clock is used as a reference oscillation source to perform time management with sufficiently high accuracy. The orbit 15a of the first observation satellite and the orbit 15b of the second observation satellite do not have to be the same, and, for example, the orbit altitude and the orbit inclination angle may be different.

Next, the principle of altitude extraction by image stereoscopic viewing will be described with reference to FIG. FIG. 3 is a diagram showing the principle of altitude extraction based on stereoscopic parallax when an optical sensor using a line sensor is used as an imager. In the figure, 12 is the earth, 14a is the line of sight of the first imaging device, 14b is the line of sight of the second imaging device, 17a is the position A of the first observation satellite,
17b is the position B of the second observation satellite, 18 is the intersection C of the line of sight, 19 is the observation point D on the surface of C, 20a is the parallel line with the line of sight of the first imager passing through D, and 20b is D A line parallel to the line of sight of the second image pickup device passing through, 21a is a position of D in the image of the first image pickup device, and 21b is D in the image of the second image pickup device.
Is the position. The position A17a of the first observation satellite and the position B17b of the second observation satellite are determined using the navigation satellite, and the angles θ1 and θ2 are determined from the navigation satellites received by three or more antennas provided on the same observation satellite. The data is used to analyze and determine the relative relationship of the antenna position coordinates. Therefore, the intersection C18 of the lines of sight 14a of the first image pickup device and the line of sight 14b of the second image pickup device is determined, so that the coordinate position of C is determined when considered on a plane including points A, B, and C. Then, the distance H between the straight line AB and the point C is also determined. If the elevation difference h between the observation point D on the ground surface and the point C is 0, the point D is the first
Since the line of sight 14a of the second image pickup device and the line of sight 14b of the second image pickup device coincide with the intersection C, the position of the point D projected on the image coincides with the points A and B. If it is not 0, the position of the point D projected on the image passes through the parallel line 20a with the line of sight of the first image pickup device passing through D and the parallel line 20b with the line of sight of the second image pickup device passing through D, respectively. The image is captured at the position E21a of D in the image of the first image pickup device and the position F21b of D in the image of the second image pickup device. A in the image
The E distance x1 and the AF distance x2 are parallax equivalent to the ground conversion distance, and the altitude h can be calculated as h = x1 / tan θ1 + x2 / tan θ2. Note that with an optical sensor that uses a line sensor, the imaging location changes according to the progress of the satellite while keeping the field of view constant, so the altitude h was calculated from the distances AE and AF, but in the case of stereoscopic vision by aerial photography, The altitude can be calculated from the angle difference between AC and AD in the figure. Note that, in FIG. 3, the plane geometry is described, but in three-dimensional geometry, the elevation can be extracted by stereoscopic vision with the same idea. As described above, if the satellite position data and the angle data of the line-of-sight direction are used, the position coordinates of the point C18, which is the reference for the elevation calculation, can be determined, and the point D18 is actually displayed in the continuous image.
The feature of this method is that the altitude of D is obtained based on the parallax of the place where the image is captured. In the present invention, the relative positions of three or more antenna mounting points where the three antennas mounted on the observation satellite 6 are present. The positional relationship is measured on the ground in advance, and the elevation data can be extracted by using the angle data obtained by calculating the position coordinates of any three points and the normal direction vector of the plane where the three points exist. When using the information of 4 or more antennas, the data with poor reception sensitivity of the navigation satellite signal may be deleted, or the data may be subjected to statistical processing such as averaging to improve accuracy. Becomes

Next, a specific example of the database will be described with reference to FIG. FIG. 4 is a diagram showing an example of the structure of a database. In the figure, 7 is a database, 22 is image data, 23 is an image header, 27 is each pixel data, 24 is an image data block, 26 is a position data block, and 29 is an angle. A data block, 28 is a header, 30 is satellite position data, and 33 is angle data.

The database 7 includes an image data block 24, a position data block 26, and an angle data block 2.
The data received from the observation satellite is recorded. The image data 22 is composed of an image header 23, a header 28, and each pixel data 27, and indicates an information group regarding a series of images. Since the header 28 includes time information, each pixel data 27 is associated with the position data 30 and the angle data 33 by referring to the header 28. At this time, the acquisition frequency of the position data and the angle data can be arbitrarily set depending on the vibration degree of the observation satellite and the required level of the altitude analysis accuracy, so that the image data, the position data and the angle data are necessarily in one-to-one correspondence via the header 28. No need.

[0054]

Next, an example of accurately determining the position of the observation satellite using the navigation satellite will be described with reference to FIG. Figure 5
Is a diagram showing an example of a method for improving the position accuracy by using a plurality of navigation satellite data, in which 6 is an observation satellite and 11
a is the first navigation satellite, 11b is the second navigation satellite, 11c
Is a third navigation satellite, 11d is a fourth navigation satellite, 10 is a ground station, and 12 is the earth. Since the position of the navigation satellite 11 is accurately determined, in order to determine the position of the observation satellite 6 in outer space, three different navigation satellites 11a, 11 are used.
It is only necessary to know the distance by receiving the navigation signals from b and 11c. Further, in order to eliminate the influence of an error due to a signal propagation time delay until the signal from the navigation satellite is received, the navigation satellite 1
When the signal from 1d is received, the orbit of each navigation satellite is known, so the relative position of the navigation satellite at each time is known, and the position accuracy is improved. In addition, in order to eliminate the effects of the ionosphere while the signals from the navigation satellites propagate, the ground station 1
Since the position coordinate of 0 can be accurately measured in advance, the positions of the observation satellite 6 and the ground station 10 at a specific time are measured by the signals from the navigation satellites 11a, 11b, 11c, 11d, and the position of the ground station is measured. If the position coordinate of the observation satellite 6 is obtained by the difference using the coordinate as a reference, the position accuracy is further improved.

Embodiment 2. FIG. 6 is a configuration diagram showing a second embodiment of the present invention, in which 1a is a first image pickup device for pointing the surface of the earth, and 1b.
The angle formed by the line of sight of the image pickup device and the vertical direction is the first
Second image pickup device different from the image pickup device 1a of FIG. 2, 2 is a clock, 3 is a navigation satellite signal receiver, 4a is a first antenna for receiving navigation satellite signals, 4b is a second antenna, and 4c is a third antenna. An antenna, 5 is a signal processing circuit, 6 is an observation satellite that flies in an orbit capable of taking an image of the entire surface of the earth with the image pickup device 1, 7 is a database that records image data and the position and angle data of the observation satellite together with time information, 10 is a ground station, 11 is a navigation satellite, and 12 is the earth.

In the figure, the first observation satellite 6
The image pickup device 1a and the second image pickup device 1b pick up images of the surface of the earth 12 in accordance with the image pickup timing signal generated by the clock 2.
The image data is transmitted to the signal processing circuit 5. Further, the timepiece 2 transmits time information when the image pickup timing signal is generated to the signal processing circuit 5. The navigation satellite signal receiver 3 receives the position information of the satellite at that time from the navigation satellite 11 by the first antenna 4a, the second antenna 4b, and the third antenna 4c according to the timing signal generated by the clock 2. To the signal processing circuit 5. The signal processing circuit 5 adds incidental information such as identification information to the received time information, image data, position data, and angle data, and then processes the data into a format that can be transmitted to the ground, and a ground station via a transmitter (not shown). Transmit to 10. At this time, the angle data is calculated by obtaining the normal direction vector of the plane in which three points are present based on the position coordinates of three or more points in which the three antennas mounted on the observation satellite 6 are present. Regarding the processing after transmission, the first embodiment
Is the same as.

Third Embodiment FIG. 7 is a configuration diagram showing a third embodiment of the present invention, in which 1 is an image pickup device which points the surface of the earth, 2 is a clock, and 3 is
Is a navigation satellite signal receiver, 4a is a first antenna for receiving navigation satellite signals, 4b is a second antenna, and 4c is a third antenna.
, 5 is a signal processing circuit, 6 is an observation satellite that flies in an orbit that allows the imager 1 to image the entire surface of the earth,
7 is a database for recording image data and position data and angle data of observation satellites together with time information, 10 is a ground station, 11 is a navigation satellite, 12 is the earth, 28 is a view direction changing machine, and as a view direction changing machine 28 By rotating the entire image pickup device by a drive mechanism that rotates about an axis orthogonal to the satellite traveling direction, it is possible to change the angle formed by the visual field direction and the vertical direction. Further, even if a rotating mechanism with a reflecting mirror for changing the visual field direction is installed in the visual field direction of the image pickup device, the visual field direction can be changed similarly. If the visual direction changing device 28 is operated and the same place on the earth is imaged a plurality of times, a set of image data of the same place viewed from different directions can be obtained, and thus the shape of the earth can be analyzed as in the first embodiment. Becomes Other operations are the same as those in the second embodiment.

FIG. 8 is a block diagram showing a fourth embodiment of the present invention. In the figure, 1 is an image pickup device which points the surface of the earth, 2 is a clock, 3 is a navigation satellite signal receiver, and 4a is a navigation satellite signal. A first antenna for receiving the signal, 4b is a second antenna, 4c is a third antenna, 5 is a signal processing circuit, 6 is an observation satellite that flies in an orbit capable of capturing an image of the entire surface of the earth with the image pickup device 1, 7 is a database for recording image data and position data and angle data of observation satellites together with time information, 10 is a ground station, 11 is a navigation satellite, 12 is the earth, 41
Is an attitude changing machine for changing the attitude of the observation satellite 6, and the attitude changing machine 41 can be a method of injecting a thruster or a method of changing the rotation speed of the momentum wheel. As a result, the imaging device 1
It is possible to change the angle between the line-of-sight direction and the vertical direction.
If the posture changing machine 41 is operated and the same place on the earth is imaged a plurality of times, a set of image data of the same place viewed from different directions can be obtained. Therefore, it is possible to analyze the earth shape in the same manner as in the first embodiment. Become. Other operations are the same as those in the second embodiment.

Fifth Embodiment 9 is a block diagram showing a fifth embodiment of the present invention, in which 2 is a clock, 3 is a navigation satellite signal receiver, 4a is a first antenna for receiving navigation satellite signals, and 4b is a second antenna. Antenna, 4c is a third antenna, 5 is a signal processing circuit,
6 is an observation satellite, 7 is a database, 10 is a ground station, 11
Is a navigation satellite, 12 is the earth, and 8 is an imaging radar that points the surface of the earth. If the imaging radar 8 is, for example, a synthetic aperture radar, it is possible to obtain a precise surface image of the earth like an optical imager. Therefore, a pair of images for stereoscopic viewing can be acquired by combining images of the same place on the earth acquired from different directions. Since the image of the synthetic aperture radar includes random noise called speckle noise, the number of looks at which the same point is picked up is set to plural times when a series of images is acquired.
Next, if the images at the same point are averaged in the initial correction process of the imaging radar 8, speckle noise can be removed, and the error in the contrast of the image can be removed. In addition, since distortion called foreshortening occurs in the image of the synthetic aperture radar, a geometric correction unique to the imaging radar 8 is performed by performing a correction process. Further, as in the case of the optically picked-up image, since it is possible to perform processing for matching corresponding points of corresponding places in a plurality of images in accordance with the grayscale features of the image, it is possible to perform elevation extraction by stereoscopic vision. Similarly, it becomes possible to analyze the shape of the earth. Other operations are similar to those of the first embodiment. Further, the same operation as that of the second embodiment can be performed by mounting the imaging radar 8 that points in different directions on the same observation satellite 6. Further, by adding a function of changing the visual field direction with respect to the satellite traveling direction to the imaging radar 8, the same operation as that of the third embodiment can be performed. Further, by adding the attitude changing function to the observation satellite 6, the same operation as that of the fourth embodiment can be performed. It is also possible to measure the relative height difference in a series of images by interfering a plurality of image data and generating an interferogram, instead of parallax due to stereoscopic vision.
It can be used as auxiliary data for data verification.

Sixth Embodiment 10 is a configuration diagram showing a sixth embodiment of the present invention.
In the drawing, 1 is an image pickup device, 2 is a clock, 3 is a navigation satellite signal receiver, 4a is a first antenna for receiving navigation satellite signals, 4b is a second antenna, 4c is a third antenna, 5
Is a signal processing circuit, 6 is an observation satellite, 7 is a database, 1
0 is a ground station, 11 is a navigation satellite, 12 is the earth, and 9 is an altimeter that points in the vertical direction of the earth. As the altimeter 9, for example, laser light is emitted toward the surface of the earth, and the reflected light from the surface of the earth is detected. A laser radar is used that measures the time difference between the two to measure altitude. The altimeter 9 measures the altitude to the ground surface according to the measurement timing signal generated by the clock 2 and transmits the data to the signal processing circuit 5. If the irradiation beam width is set to be equal to the interval between adjacent orbits of the observation satellite 6, data can be acquired all over the surface of the earth. As for the satellite traveling direction, data can be acquired without duplication if data is acquired at a time interval at which the satellite traveling distance becomes equal to the adjacent orbit interval. If the frequency of data acquisition is increased from this time interval to increase the number of times of data acquisition at the same place, resampling can increase the resolution in the satellite traveling direction. The signal processing circuit 5 adds time data at each timing of measuring altitude data, and then transmits it to the ground in the same manner as the image data. The satellite position data and the pointing angle data of the altimeter are recorded in the database 7 as in the first embodiment, the altitude data and the position data are associated with each other by referring to the time, the coordinates of the earth surface and the altitude thereof are analyzed, and the database 7 To record. Note that the angle data is calculated by obtaining the normal direction vector of the plane where the three points are present based on the position coordinates of the three points where the three antennas mounted on the observation satellite 6 are present, as in the first embodiment. is there.
As a method of using the data in the database, since the position coordinate data analyzed by the stereoscopic vision according to the first, second, third, and fourth embodiments has a higher resolution in the undulating land area, the data by the altimeter 9 is treated as an auxiliary treatment. Become. On the other hand, in a flat area over a wide area on land or in the ocean, the first embodiment,
In the stereoscopic view of 2, 3, and 4, it is difficult to perform the matching process for making the same positions in the paired images correspond to each other, and the error factor becomes large. Therefore, the data by the altimeter 9 is preferentially used. In a place where the land area and the ocean area are mixed in the continuous image, the stereoscopic data according to the first, second, third, and fourth are given priority,
Embodiment 1 in the boundary area data between the ocean area and the land area,
It is used to verify that there is no inconsistency between the stereoscopic data of 2, 3, and 4 and the data of the altimeter 9. Since the data of the altimeter 9 including the land area data is stored in the database 7, it is useful to refer to it when only the altitude information approximate value is desired.

Embodiment 7. FIG. 11 is a configuration diagram showing image data according to the seventh embodiment of the present invention, and shows a method of adding time information by taking a line sensor type image pickup device as an example. In the figure, 22 is image data, 23 is an image header, 24 is line data, 25 is a line header, 2
Reference numeral 6 indicates data of the same image pickup timing, and 27 indicates each pixel data. In an image pickup device using a line sensor, a plurality of pixels are arranged in a horizontal row perpendicular to the satellite traveling direction, and each pixel data in the horizontal row is acquired at the same imaging timing.
When the imaging is repeated at the specified time interval, the satellite position advances in accordance with the time progress, so an image in the direction of travel can be acquired, and two-dimensional image data is obtained. The configuration of the image data 22 includes an image header and each pixel data, as in the conventional technique. In the present invention, a set of each pixel data 27 newly acquired at the same timing is used as the data of the same imaging timing, and the line header 25 is added to add the line data 2
6 is composed. Further, not only the image acquisition year / month / day but also the time when the image pickup is started is described in detail in the image header. For example, in the case of an imaging device that takes an image every 40 microseconds, 1
Describe the time up to the microsecond unit. Also, record the last three digits of the time as each line header. Time is a variable that increases monotonically, so you will not lose track of the exact time even if the number of digits carries up. In the example of FIG. 11, 199
This is an example in which imaging is started at 10: 20: 0.000901 seconds on July 9, 1997, and imaging is performed approximately every 40 microseconds. However, it is a problem if the amount of data becomes huge due to the addition of time information. In this example, the image pickup start time is recorded in the image header, and only the three-digit number on the order of microseconds is recorded in the line header. The imaging time of the fourth column is 1024 microseconds, but the time will not be lost even if the first digit is omitted. However, the satellite position data and the line-of-sight angle data do not necessarily have to be acquired at the same frequency as the image data is captured. Needless to say, incidental information, information for identifying the data format, error correction signals, and the like, which have been recorded by the conventional technique, may be recorded in the image header or the line header.

Embodiment 8. FIG. 12 is a diagram showing an example of an anti-aircraft sign according to Embodiment 8 of the present invention, in which 1a is a first imager, 1b is a second imager, 6 is an observation satellite, and 31a is a first anti-aircraft. Signs, 31b is a second air sign, 31c is a third air sign, 31d is a fourth air sign, 31e is a fifth air sign, 32a is a first air sign group, and 32b is a second air sign. All the anti-aircraft signs 31 are a group, and the position coordinates measured by the navigation satellite are already recorded in the earth shape database. The anti-aircraft sign 31 is a circle or a straight line that is several times larger than the surface resolution of the image pickup device 1,
The center position can be identified by looking at the captured image with the geometrical shape drawn with diagonal lines. Furthermore, the anti-aircraft sign group 32
Is a geometrical shape in which a plurality of the anti-aircraft markers 31 are arranged,
In the example of FIG. 12, with the first anti-aircraft sign 31a as a reference, the second anti-aircraft sign 31b and the third anti-aircraft sign 31c are arranged in the satellite traveling direction and the orthogonal direction, and the second anti-aircraft sign 31b and the third anti-aircraft sign 31b are arranged. The distance of the anti-aircraft sign 31c is set to be slightly smaller than the range of the image acquired by the image pickup device 1. Similarly, the fourth anti-aircraft sign 31d and the fifth anti-aircraft sign 31e are aligned in the satellite traveling direction, and the second anti-aircraft sign 31b and the third anti-aircraft sign 31 are arranged.
The distance c is also set to be slightly smaller than the range of the image acquired by the image pickup device 1. By looking at the image taken so that the first anti-aircraft sign 31a appears in the center, the position coordinates of each anti-aircraft sign are known, so that the angle of the line-of-sight direction of the satellite can be corrected. Further, FIG. 11 shows an example in which a plurality of image pickup devices pointing in different directions are fixed on the same observation satellite 6, but the first image pickup device 1a sets the first anti-aircraft sign group 32a at the same image pickup timing. The second image pickup device 1b is the second anti-aircraft sign group 32.
By imaging each of b, it is possible to correct the view direction error of the imaging device due to the thermal deformation of the observation satellite 6 or the like.

Next, a method of correcting the angle in the line-of-sight direction will be described with reference to FIG. FIG. 13 is a schematic diagram in which the anti-aircraft sign 31 is imaged in the image data acquired by the image sensor of the line sensor system, and is an example when the image data has the configuration according to the sixth embodiment. In the figure, 22 is image data, 2
3 is an image header, 25 is a line header, 31a is a first anti-aircraft sign, 31b is a second anti-aircraft sign, and 31c is a third anti-aircraft sign. When the calculation result obtained from the satellite position data and the angle data in the line-of-sight direction is T1 as the time when the observation satellite images the first anti-aircraft sign 31a, the corresponding time in the image data 22 is a combination of the image header 23 and the line header 25. Corresponding, and in the example of FIG. 13, the first anti-aircraft sign 31a should be imaged at the position of T1 = t13, but since the time of actual imaging is t9, there is an error in the value recorded in the angle data, In fact, it can be seen that the angle was tilted in the satellite traveling direction rather than the value of the angle data. In addition, since the amount of inclination can be converted from the ground-converted distance of the image, the angle of the line-of-sight direction can be calibrated on the ground using the anti-aircraft sign. Further, if the line sensor is set orthogonally to the satellite traveling direction, the first anti-aircraft sign 31a and the second anti-aircraft sign 31b.
Although the third anti-aircraft sign 31c should be imaged at the same timing, the imaged times are different in the example of FIG. Since this shift amount can be converted into the inclination angle of the line sensor by using the ground conversion distance of the image, the angle in the line-of-sight direction can be calibrated on the ground using the anti-aircraft sign.

Ninth Embodiment FIG. 14 is a block diagram showing a ninth embodiment of the present invention, in which 1 is an image pickup device which points the surface of the earth, 2 is a clock, 3 is a navigation satellite signal receiver,
4a is a first antenna for receiving navigation satellite signals, and 4b
Is a second antenna, 4c is a third antenna, 5 is a signal processing circuit, 6 is an observation satellite that flies in an orbit capable of capturing an image of the earth surface with the image pickup device 1, 7 is image data and position data of the observation satellite. And a database for recording angle data together with time information, 10 is a ground station, 11 is a navigation satellite, 12 is the earth, and 40 is a computer. In the figure, the navigation satellite signal receiver 3 displays the first signal according to the timing signal generated by the clock 2.
The antenna 4a, the second antenna 4b, and the third antenna 4c receive the position information of the satellite at that time from the navigation satellite 11 and transmit it to the computer 40. The computer 40 obtains angle vector data based on the position coordinates of the three points received from the navigation satellite signal receiver 3 to obtain the normal direction vector of the plane where the three points exist, and transmits the angle data to the signal processing circuit 5.
The signal processing circuit 5 adds incidental information such as identification information to the time information received from the clock 2, the image data received from the image pickup device 1 and the position data received from the computer 40, and then processed into a format that can be transmitted to the ground. Then, the data is transmitted to the ground station 10 via a transmitter (not shown). Other operations are similar to those of the first embodiment.

[0066]

According to the first aspect of the present invention, by utilizing the image data of the surface of the earth as seen from space, it is possible to measure without installing a measuring instrument on the ground, so that the entire surface of the earth is quantified as three-dimensional information. The effect is that you can do it. It also has the effect of being able to measure data in areas where human activity does not reach.
In addition, if one set of equipment is built, there is no need for other ground equipment, so there is an effect that a huge amount of data can be acquired at low cost.

By measuring the orbital positions of a plurality of observation satellites and calculating the pointing angle direction of the observation satellites from the position data, the position and angle of the observation satellites when the image is acquired can be determined. There is an effect that the absolute coordinates of the ground surface can be measured without a reference point such as an anti-aircraft sign. Further, there is an effect that aerial triangulation can be performed without an angle detector.

Further, since it is a geometrical measurement method that does not include the gravity effect, there is an effect that the measurement can be performed without being influenced by the bias of gravity. In addition, it is possible to realize an observation satellite that flies in an orbit capable of capturing an image of the entire surface of the earth with an on-board imager, and it is possible to perform high-resolution measurement that corresponds to small undulations.

Further, since the time is managed by using the atomic clocks having high frequency stability and mutually adjusted, there is an effect that it is possible to measure with a common time reference regardless of time and place. Further, since the earth's rotation is not used as the time reference, there is an effect that the time absolute accuracy is high, and high-accuracy measurement with few errors due to the time accuracy can be performed.

Moreover, since the earth surface position coordinates can be measured by a single coordinate system operating a navigation satellite, there is an effect that maps of each country can be created on the unified coordinate system. Moreover, there is an effect that the maps of each country can be aligned with an accuracy of about several tens of meters.

Since the accuracy of time and position measurement is improved by adopting an atomic clock and using a navigation satellite, there is an effect that measurement can be performed with sufficiently high accuracy on a global scale.

Further, according to the second invention, there is an effect that the amount of data that can be acquired within a limited satellite lifetime increases. Further, most of the satellite position data, the line-of-sight angle data, and the incidental information recorded in the database can be shared by the first image pickup device and the second image pickup device, so that the data amount can be reduced. In addition, the satellite position error, which is an error factor when extracting the altitude, and the error of the angle data calculated from the position data are equal to each other and offset, which improves the analysis accuracy. Further, it goes without saying that the same effect as that of the first embodiment can be obtained.

Further, according to the third aspect of the present invention, since it is possible to select the ground observation target, it is easy to acquire the data of the place where it is easy to be covered with clouds and where it is difficult to acquire the image data within the limited satellite life period. There is an effect. In addition, there is an effect that the altitude extraction accuracy can be improved by selectively acquiring a large amount of data in a place where the altitude difference is large and the altitude extraction error is large in the proximity region. Further, by obtaining images taken from a plurality of directions, which are three or more directions, in a place having a complicated topographical feature, it becomes easier to find corresponding points of each image, and thus there is an effect that an elevation extraction error due to an image alignment error can be reduced. . Further, even if there is a terrain that is behind a high mountain when viewed from a specific direction, the data can be interpolated by the stereoscopic data from another direction, which has the effect of increasing the reliability of the data. It goes without saying that the same effect as the first invention is obtained.

According to the fourth aspect of the invention, the ground observation target to be observed by the image pickup device can be selected by changing the directivity angle of the observation satellite, so that it is difficult to acquire image data as in the third aspect of the invention. There is an effect that it is easy to acquire location data within a limited satellite lifetime. Furthermore, the third embodiment
Since it is necessary to measure the viewing angle operated by the viewing direction changer with a separate angle detector and correct the angle data calculated from the position data from the navigation satellite, the data processing is complicated and the angle error tends to be large. Although there is a problem, according to the present invention, the positional data acquired by the three antennas has a relative relationship with the line-of-sight direction of the image pickup device,
This has the effect of enabling accurate measurement with simple data processing. Further, it goes without saying that the same effect as the third invention is obtained.

According to the fifth aspect of the invention, since the imaging radar using microwaves can transmit image data through clouds unlike an optical imager in which images are blocked by clouds,
This has the effect of reliably acquiring image data in the tropics and near the equator. Moreover, in the high latitude region and polar regions where the reflected light of the sun is small with an optical imager, the image is too dark to be used for analysis, whereas the imaging radar using microwaves can acquire the image of the region without sunlight irradiation. For,
There is an effect that it is possible to effectively obtain topographical data in the polar regions that characteristically represent the elliptical shape of the earth.

According to the sixth aspect of the invention, there is an effect that it is possible to observe the shape of a flat area over a wide area such as the sea or the desert without any characteristic. In addition, since the average elevation over a wide area can be grasped in the land area, it is useful for grasping the rough shape of the earth. Further, in the case of flat terrain such as the ocean, it is sufficient to broaden the beam emitted by the altimeter to measure the average altitude, so limiting the measurement target has the effect that the conventional altimeter can be used.

According to the seventh aspect of the invention, the time at which the image is picked up can be grasped accurately, so that the position can be measured with high accuracy. Further, since the time history of all the image pickup timings is attached to the image data, there is an effect that it is possible to correct the sway and attitude change of the satellite by utilizing the hygienic position and the line-of-sight direction information at each image pickup time. In addition, since the time is managed by using the atomic clocks with high frequency stability and mutually adjusted, there is an effect that it is possible to measure with a common time reference regardless of time and place.

According to the eighth aspect of the invention, since the position and angle can be calibrated on the ground as a point whose position coordinates are known in the image, there is an effect that the measurement can be performed with sufficiently high accuracy on a global scale. Further, since the time history of the image pickup timing is attached to the image data and the satellite position and line-of-sight direction information at the image pickup time can be calibrated, there is an effect that the pointing error of the image pickup device and the satellite attitude variation can be corrected. Further, since the number of ground calibration points in the database increases with the increase in the number of anti-aircraft signs, there is an effect that the image data conventionally stored in the database can be reused and the data can be updated with higher accuracy than ever.

According to the ninth invention, since the angle data is calculated on the orbit of the observation satellite, the time information, the image data, the position information and the angle information are transmitted at the stage of transmitting the data on the ground via the signal processing circuit. Since all of them are prepared, there is an effect that analysis processing such as stereoscopic processing can be performed even if the ground processing equipment is simple. Further, since the ground processing equipment can be simple, there is an effect that the ground processing equipment can be set up in many places at low cost in a short time.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of an earth shape measuring apparatus according to the present invention.

FIG. 2 is a schematic diagram of a satellite orbit according to the first embodiment of the present invention.

FIG. 3 is a diagram showing the principle of elevation extraction based on the stereoscopic parallax of the earth shape measuring apparatus according to the present invention.

FIG. 4 is a diagram showing a configuration of a database of the earth shape measuring apparatus according to the present invention.

FIG. 5 is a diagram showing an example of a method for accurately determining absolute position coordinates of an observation satellite of the earth shape measuring apparatus according to the present invention.

FIG. 6 is a configuration diagram showing a second embodiment of the earth shape measuring apparatus according to the present invention.

FIG. 7 is a configuration diagram showing a third embodiment of the earth shape measuring apparatus according to the present invention.

FIG. 8 is a configuration diagram showing a fourth embodiment of the earth shape measuring apparatus according to the present invention.

FIG. 9 is a configuration diagram showing a fifth embodiment of the earth shape measuring apparatus according to the present invention.

FIG. 10 is a configuration diagram showing a sixth embodiment of the earth shape measuring apparatus according to the present invention.

FIG. 11 is a configuration diagram showing a seventh embodiment of the earth shape measuring apparatus according to the present invention.

FIG. 12 is a diagram showing an example of an anti-aircraft sign according to an eighth embodiment of the earth shape measuring apparatus according to the present invention.

FIG. 13 is a diagram illustrating a method of correcting the angle in the line-of-sight direction according to the eighth embodiment of the earth shape measuring apparatus according to the present invention.

FIG. 14 is a configuration diagram showing a ninth embodiment of the earth shape measuring apparatus according to the present invention.

FIG. 15 is a diagram showing a conventional earth shape measuring apparatus.

FIG. 16 is a diagram showing a satellite triangulation device which is an example of a conventional earth shape measuring device.

FIG. 17 is a principle diagram of satellite triangulation, which is an example of a conventional earth shape measuring apparatus.

FIG. 18 is a diagram showing an aerial triangulation device which is another example of the conventional earth shape measuring device.

FIG. 19 is a diagram showing another example of a conventional earth shape measuring apparatus.

[Explanation of symbols]

1 imager, 2 clock, 3 navigation satellite signal receiver, 4
Antenna, 5 signal processing circuits, 6 observation satellites, 7 database, 8 imaging radar, 9 altimeter, 10
Ground station, 11 navigation satellites, 12 earth, 13 spheroid, 22 image data, 23 image header, 24 image data block, 25 line header, 26 position data block, 28 header, 29 angle data block, 31 anti-aircraft sign, 32 Anti-aircraft sign group, 34 geodesic satellites.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01C 11/00 G01C 15/00 101 G01C 15/00 102 G01C 15/00 104 G01S 5/02

Claims (9)

(57) [Claims] 1. An image pickup device for directing the surface of the earth, a clock for generating a timing signal by measuring the time when the image pickup device carries out an image pickup, an image signal obtained by the image pickup device and a timing signal generation time when the clock is generated. Signal processing circuit that processes data into a form that can be transmitted to the ground by associating with , and position information of the navigation satellite according to the timing signal generated by the clock
An antenna for receiving a signal, a navigation satellite signal receiver for transmitting the signal received by the antenna together with time information to the signal processing circuit, and an observation satellite flying in an orbit capable of imaging the surface of the earth with the imager, The database that records the image data acquired by the image pickup device and the position data acquired by the navigation satellite signal receiver together with the time information when the clock generated the timing signal, and the position coordinates of the earth surface, and the radio wave propagation time. In an earth shape measuring device composed of a plurality of navigation satellites whose orbital positions are known to generate radio waves for measuring distances by utilizing, the angles formed by the line-of-sight direction and the vertical direction of the image pickup device are different from each other. It has multiple observation satellites and has three or more antennas fixed as different antennas on each observation satellite. Earth shape measuring apparatus, characterized in that. 2. An image pickup device directed to the surface of the earth, a timepiece that generates a timing signal by measuring the time when the image pickup device performs image pickup, an image signal obtained by the image pickup device and a timing signal generation time when the clock is generated. Signal processing circuit that processes data into a form that can be transmitted to the ground by associating with , and position information of the navigation satellite according to the timing signal generated by the clock
An antenna for receiving a signal, a navigation satellite signal receiver for transmitting the signal received by the antenna together with time information to the signal processing circuit, and an observation satellite flying in an orbit capable of imaging the surface of the earth with the imager, The database that records the image data acquired by the image pickup device and the position data acquired by the navigation satellite signal receiver together with the time information when the clock generated the timing signal, and the position coordinates of the earth surface, and the radio wave propagation time. In an earth shape measuring device composed of a plurality of navigation satellites whose orbital positions are known to generate radio waves for measuring distances using the earth shape measuring device, the angles formed by the line-of-sight direction and the vertical direction are different from each other as the imaging device. Three or more antennas equipped with multiple imagers on one observation satellite and fixed as different antennas at different positions on the observation satellite. Earth shape measuring apparatus characterized by comprising a. 3. An image pickup device directed to the surface of the earth, a timepiece that generates a timing signal by measuring the time when the image pickup device carries out an image pickup, an image signal obtained by the image pickup device and a timing signal generation time when the clock is generated. Signal processing circuit that processes data into a form that can be transmitted to the ground by associating with , and position information of the navigation satellite according to the timing signal generated by the clock
An antenna for receiving a signal, a navigation satellite signal receiver for transmitting the signal received by the antenna together with time information to the signal processing circuit, and an observation satellite flying in an orbit capable of imaging the surface of the earth with the imager, The database that records the image data acquired by the image pickup device and the position data acquired by the navigation satellite signal receiver together with the time information when the clock generated the timing signal, and the position coordinates of the earth surface, and the radio wave propagation time. In an earth shape measuring device composed of a plurality of navigation satellites whose orbital positions are known to generate radio waves for measuring distances using the earth shape measuring device, by rotating the image pickup device, the line-of-sight direction and the vertical direction of the image pickup device. Is equipped with a line-of-sight direction changing device for changing the angle formed by, and as the above-mentioned antenna, three or more antennas fixed at different positions on the observation satellite are provided. Earth shape measuring apparatus, characterized by. 4. An image pickup device directed to the surface of the earth, a timepiece which generates a timing signal by measuring the time when the image pickup device carries out an image pickup, an image signal obtained by the image pickup device and a timing signal generation time when the clock is generated. Signal processing circuit that processes data into a form that can be transmitted to the ground by associating with , and position information of the navigation satellite according to the timing signal generated by the clock
An antenna for receiving a signal, a navigation satellite signal receiver for transmitting the signal received by the antenna together with time information to the signal processing circuit, and an observation satellite flying in an orbit capable of imaging the surface of the earth with the imager, The database that records the image data acquired by the image pickup device and the position data acquired by the navigation satellite signal receiver together with the time information when the clock generated the timing signal, and the position coordinates of the earth surface, and the radio wave propagation time. In an earth shape measuring device composed of a plurality of navigation satellites whose orbital positions that generate radio waves for measuring distances by utilizing the earth shape measuring device, Three or more antennas that are equipped with attitude changers that change the angle formed and that are fixed as different antennas at different positions on the observation satellite. Earth shape measuring apparatus characterized by comprising a. 5. The earth shape measuring apparatus uses an imaging radar as an image pickup device.
The earth shape measuring device according to any one of to 4. 6. The earth shape measuring apparatus further comprises an altimeter for emitting a signal toward the surface of the earth and measuring the altitude to the surface of the earth using the propagation time until the reflected signal arrives. The earth shape measuring device according to any one of 1 to 4. 7. The earth shape measuring apparatus according to claim 1, wherein the signal processing unit adds the times of all the image pickup timings to the image data and records it in the database.
The earth shape measuring device according to any one of to 4. 8. The earth shape measuring device further comprises an anti-aircraft sign whose position coordinates on the surface of the earth are set to locations already measured by a navigation satellite, and a database which records the position coordinates of the location where the anti-aircraft sign is set. Claims 1-4
The earth shape measuring device according to any one. 9. In the earth shape measuring apparatus, the observation satellite comprises a computer, and the navigation satellite signal receiver analyzes the position data of three points acquired from three antennas by the computer to analyze the position data in the inertial space. The earth shape measuring apparatus according to claim 1, wherein the pointing angle of the image pickup device is calculated based on the relative position coordinates of the points, and is transmitted to the signal processing unit as angle data.